Fix dereferencing on local variables to ignore whitespace

opal · Dec 7, 2013 · 4cd3580 · 4cd3580
1 parent 4133522
commit 4cd3580
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Showing 4 changed files with 33 additions and 10 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -57,6 +57,9 @@
 
 *   Support single character strings (using ? prefix) with escaped characters.
 
+*   Fix lexer to detect dereferencing on local variables even when whitespace
+    is present (`a = 0; a [0]` parses as a deference on a).
+
 ## 0.5.5 2013-11-25
 
 *   Fix regression: add `%i[foo bar]` style words back to lexer

diff --git a/lib/opal/parser.rb b/lib/opal/parser.rb
@@ -9,9 +9,10 @@ class Parser < Racc::Parser
     attr_reader :lexer, :file, :scope
 
     def parse(source, file = '(string)')
-      @lexer = Lexer.new(source, file)
       @file = file
       @scopes = []
+      @lexer = Lexer.new(source, file)
+      @lexer.parser = self
 
       self.parse_to_sexp
     end

diff --git a/lib/opal/parser/lexer.rb b/lib/opal/parser/lexer.rb
@@ -29,6 +29,7 @@ class Lexer
     attr_accessor :strterm
     attr_accessor :scanner
     attr_accessor :yylval
+    attr_accessor :parser
 
     def initialize(source, file)
       @lex_state  = :expr_beg
@@ -44,6 +45,10 @@ def initialize(source, file)
       @scanner_stack = [@scanner]
     end
 
+    def has_local?(local)
+      parser.scope.has_local?(local.to_sym)
+    end
+
     def cond_push(n)
       @cond = (@cond << 1) | (n & 1)
     end
@@ -483,6 +488,8 @@ def heredoc_identifier
     end
 
     def process_identifier(matched, cmd_start)
+      last_state = @lex_state
+
       if scanner.peek(2) != '::' && scan(/:/)
         @lex_state = :expr_beg
         self.yylval = matched
@@ -571,6 +578,10 @@ def process_identifier(matched, cmd_start)
         @lex_state = :expr_end
       end
 
+      if ![:expr_dot, :expr_fname].include?(last_state) and has_local?(matched)
+        @lex_state = :expr_end
+      end
+
       return matched =~ /^[A-Z]/ ? :tCONSTANT : :tIDENTIFIER
     end
 
@@ -888,18 +899,19 @@ def yylex
             else
               raise "Unexpected '[' token"
             end
-          elsif beg? || @space_seen
-            @lex_state = :expr_beg
-            cond_push 0
-            cmdarg_push 0
-            return :tLBRACK
+          elsif beg?
+            result = :tLBRACK
+          elsif arg? && @space_seen
+            result =  :tLBRACK
           else
-            @lex_state = :expr_beg
-            cond_push 0
-            cmdarg_push 0
-            return :tLBRACK2
+            result = :tLBRACK2
           end
 
+          @lex_state = :expr_beg
+          cond_push 0
+          cmdarg_push 0
+          return result
+
         elsif scan(/\]/)
           cond_lexpop
           cmdarg_lexpop

diff --git a/spec/cli/lexer_spec.rb b/spec/cli/lexer_spec.rb
@@ -100,4 +100,11 @@
       expect(parser.lexer.eof_content).to eq("")
     end
   end
+
+  describe "variable dereferencing ([])" do
+    it "handles referencing correctly on local variables in scope" do
+      expect_parsed("x = 0; x [0]").to eq([:block, [:lasgn, :x, [:int, 0]],
+       [:call, [:lvar, :x], :[], [:arglist, [:int, 0]]]])
+    end
+  end
 end